Hafalir, ElifTurkistani, Maram2026-04-2920262250-3153https://hdl.handle.net/20.500.14154/78816Tax non-compliance is a significant issue and has created a tax funding gap of 7.5% in Australia, which represents a tax revenue shortfall of $44.5 billion during the 2021–2022 income tax year. Tax authorities in most jurisdictions worldwide seek to establish the most effective measures to promote tax compliance. The present study investigated the determinants of tax compliance behaviours in Australia. Specifically, the study examined the effect of behavioural incentives (rewards and fines/penalties), social norms, and compliance costs on tax compliance behaviours. A quantitative experimental research design using an online survey was employed to estimate the determinants of tax compliance. The online survey, which was administered to a sample of 311 Australian taxpayers in Qualtrics, was conducted between 13 May 2025 and 22 May 2025. The final sample size, after eliminating entries associated with older participants, was 299 subjects. Data was analysed using the ordered logit regression analysis model, given the categorical attribute of the dependent variable (tax compliance). Our results revealed that only the perception of social norms and compliance costs had a significant effect on tax compliance in Australia. While the presence of social norms increased tax compliance, compliance costs negatively influenced tax compliance. We did not find a significant effect of the interaction between social norms and behavioural incentive on tax compliance. Our findings have considerable theoretical and public policy implications. Australian tax authorities need to integrate more behavioural-based nudges and eliminate tax system complexities or bureaucracy through the implementation of an e-tax filing system to improve tax compliance behaviours.45enTax ComplianceThesis